Terminal construction and method of manufacture thereof



July 5, 1966 J,- w. FARQUHAR 3,259,686

TERMINAL CONSTRUCTION AND METHOD OF MANUFACTURE THEREOF Filed July 19, 1965 3 Sheets-Sheet 1 .1575. z m. E.

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TERMINAL CONSTRUCTION AND METHOD OF MANUFACTURE THEREOF Filed July 19, 1965 3 Sheets-Sheet 2 -24 INVENTOR.

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July 5, 1966 J. w. FARQUHAR 3,259,685

TERMINAL CONSTRUCTION AND METHOD OF MANUFACTURE THEREOF Filed July 19, 1965 3 Sheets-Sheet I5 United States Patent 3,259,686 TERMINAL CONSTRUCTION AND METHOD OF MANUFACTURE THEREOF Joseph W. Farquhar, West Berlin, N.J., assignor to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Filed July 19, 1965, Ser. No. 472,914 2 Claims. (Cl. 17475) This invention relates to a novel terminal structure for conductors in the form of thin sheets, and more specifically is an improvement of copending application Serial No. 324,668, filed November 19 1963, entitled Ribbon Winding Terminations in the name of Otto Jensen, and assigned to the assignee of the present invention.

As described in the above noted application, a novel terminal construction was provided for thin conductive sheets for making a sturdy terminal which can receive suitable connection means and avoids the need for brazing a connecting terminal .to the thin sheet conductor. In that application, the end of the conductive sheet was folded 90 to the length of elongation of the conductive sheet so that the end projected at right angles to the general axis of the sheet. Thereafter, this end was folded one or more times with the crease lines again perpendicular to the general axis of the conductive sheet. The resulting terminal which extends perpendicularly from the sheet is then 7 one which has the same current carrying crosssectional area of the sheet, but whose geometry has been altered so that it is now a relatively thick body which can be easily soldered or brazed when making connections to the sheet.

The principle of the present invention is to provide a novel terminal structure similar to that described above and in the above noted copending application Serial No. 324,668, where, however, the need for making a plurality of folds is eliminated, thereby substantially improving the ease of manufacture and geometry of the resulting terminal. In addition, the present invention is applicable to materials thicker than in the foregoing application since it is only necessary to fold a single thickness of the material. In accordance with the present invention, the end of the thin sheet conductor which is a conductor having a thickness of less than approximately 150 mils and any desired width has the end thereof sliced into a plurality of parallel segments or fingers running parallel to the length of the sheet. The depth of each of the slices ends along the same line perpendicular to the length of the conductor, and each of the segments are then individually folded at right angles to the length of the thin conductive strip so that they overlie one another when all are folded. These overlying sections then extend beyond the edge of the thin conductive sheet and provide a relatively thick conductive body which can easily receive connection means in any desired manner as by brazing or clamping, or the like.

Alternatively, intermediate portions of the foil may be partially sliced and the flaps folded out to form a tap.

Accordingly, a primary object of this invention is to provide a novel terminal structure for thin conductive sheets.

Another object of this invention is to provide a novel method of manufacture of a terminal for thin conductors.

Yet another object of this invention is to provide a novel improved terminal for thin conductors and method for the manufacture thereof wherein the thin conductor is sliced into a plurality of parallel segments at the end thereof which are subsequently folded generally perpendicularly to the conductor to extend outwardly of the edge of the sheet to form a relatively high thermal inertia connection section.

These and other objects of this invention will become apparent from the following description when taken in connection with the drawings, in which:

FIGURE 1 illustrates for a first embodiment of the invention a plan view of a thin conductive sheet which has four slits placed at the end thereof.

FIGURE 2 is a side view of FIGURE 1 to illustrate that the conductor of FIGURE 1 is a thin sheet.

FIGURE 3 illustrates the first step for'the manufacture of a high thermal impedance terminal wherein the first slit segment or finger of FIGURE 1 is bent perpendicularly to the length of the sheet.

FIGURE 4 illustrates the folding of the second segment of the sheet of FIGURE 3.

FIGURE 5 illustrates all of the slit segments of FIG- URE l bent perpendicularly to define the high thermal inertia terminal structure for the thin conductive sheet.

FIGURE 6 is a top view of FIGURE 5.

FIGURE 7 is a plan view similar to FIGURE 1 of a sheet initially slit and notched in accordance with the second embodiment of the invention.

FIGURE 8 is a top view of the sheet of FIGURE 7 after the segments have been bent outwardly in the manner of FIGURES 3 through 5 where, however, all of the segments have the same point of termination because of the initial notched configuration.

FIGURE 9 is a top view of a conductor which is slitted by fingers of successively greater widths.

FIGURE 10 illustrates the conductor of FIGURE 9 after folding or forming, in end view.

FIGURE 11 is a bottom view of FIGURE 10.

FIGURE 12 is a side view illustrating the manner in which the terminal of FIGURES l0 and 11 may be welded to a conductor.

FIGURE 13 is a top view of a second embodiment of the invention wherein the individual finger segments are fanned outwardly to provide an enlarged weld area.

FIGURE 14 illustrates the manner in which the ter-' minal of FIGURE 13 may be welded to a conductor.

FIGURE 15 is a view illustrating the manner in which the invention can be applied to the formation of a tap in a centrally located region of an extending coil conductor.

Referring first to FIGURES 1 and 2, I have illustrated therein a conductive sheet 10 which has three slits 11, 12 and 13 therein to define four segments or fingers 14, 15, 16 and 17 which have the same length. The conductive sheet 10 could, for example, be a sheet conductor for a transformer winding and will have a thickness of less than mils and could have any width and any length. By way of example, the width of sheet 10 could be approximately 6", and its length could be any length required by the diameter and number of turns which are to be formed from the conductor.

Clearly, however, the thin conductor of FIGURES 1 and 2 could have many other applications with different dimensions where, for example, the thin conductive sheet is used as one conductive electrode of a wound capacitor.

' As will be seen more fully hereinafter, any number of segments or fingers 14 through 17 could have been selected, the four segments being arbitrarily selected in FIGURE 1 for purposes of illustrating the present invention.

The difliculties of making connection to thin conductive sheets are well known. In order to provide a contact mass of suitable rigidity and thermal inertia, it is common practice to braze a relatively heavy conductor to the end of the thin conductive sheet and use this conductor as a terminal. In very thin sheets, however, this brazing operation becomes very difficult, since it is quite easy to burn through the sheet during the brazing operation.

In accordance with the invention, the thin sheet is formed with a plurality of slit segments which can be bent perpendicularly to the sheet and overlie one another in their bent condition, thereby to define a relatively heavy I in FIGURE 3. Thereafter, the finger 16 is similarly bent to overlie finger 17, as shown in FIGURE 4. This bending process is then continued until all of fingers 14 through 17 are bent to the right and overlie one another, as shown in FIGURES and 6, eachof the fingers being bent on folds 18, 19, 20 and 21 for the fingers 17, 16, 15 and 14, respectively.

Note that since each of the fingers is bent individually, it is now possible to apply this concept to materials having a greater thickness than in the case of the above noted application Serial No. 324,668, wherein repeated folds are made of multiple thicknesses of the sheet conductor. Thus, in accordance with the invention, it is only necessary that the material be thin enough to be capable of being formed in accordance with the invention.

As'shown in FIGURES 5 and 6, the portions of fingers 14 through 17 projecting beyond the right-hand side 30 of conductor do not end at the same point.

In order to have a more uniform terminal conducting portion, and as illustrated in FIGURE 7, the fingers through 17 can have notch portions 32, 33 and 34 removed therefrom so that when the fingers overlie one another. after being bent, and as shown in FIGURE 8, the fingers will terminate in a common plane 35. Note that the length of the notch portion is approximately equal to the width of the respective finger.

Clearly, the length of the terminal construction extending beyond edge is determined only by the depth of slits 11 through 13, and any desired length can be attained.

Moreover, where it is desirable to alter the geometry of the extending terminal portion to have a greater thickness, it is only necessary to use a greater number of parallel slitted fingers.

The resulting terminal will then have a thickness n times the. thickness of the sheet of approximately 80 mils and a width l/n where n is the number of fingers which are bent to the terminal shape.

Referring next to FIGURE 9, I have illustrated therein the conductor 19 which is now slit into fingers 41, 42 and 43 which are progressively greater width. The fingers are then folded, as shown in FIGURES 10 and 11, so that they define a tapered terminal in which a relatively large area of each of the individual fingers are exposed, as contrasted to the arrangements of FIGURES 6 and 8 wherein only the edge regions of the individual fingers are exposed.

The arrangement of FIGURES 10 and 11 has the advantage illustrated in FIGURE 12 wherein when the terminal is to be connected to some horizontal conductor 44 by welding, the welds 45 and 46 will intimately bond to the exposed side regions of each of the fingers 41, 42 and 43 which would otherwise be covered by the upper finger 40. This type of Weld is particularly applicable to aluminum conductors.

FIGURES 13 and 14 illustrate another manner in which the successive laminations or fingers may be exposed to a weld. Thus, in FIGURE 13, the fingers 50, 51, 52 and 53 of the conductor 10 are bent atditferent angles so that they will generally fan outwardly of one another. terminal formed of fingers through 53 is welded to the conductor 44, the weld bead 54 will intimately engage the exposed surface areas of each of the fingers.

While the foregoing embodiments of the invention have illustrated fingers cut in the end of the conductor, it will be apparent that the invention is equally applicable to the formation of taps at some central point in an elongated conductor. Thus, as shown in FIGURE 15, the conductor 10 can have, for example, two or more fingers and 61 slit therein which are bent, as illustrated in the dotted lines, to provide an outwardly extending central tap for the elongated conductor 10.

Although this invention has been described with respect to its preferred embodiments, it should be understood that many variations and modifications will now be obvious to those skilled in the art, and it is preferred, therefore, that the scope of the invention be limited not by the specific disclosure herein, but only by the appended claims.

The embodiments of the invention in which an exclusive privilege or property is claimed are defined as follows:

1. A terminal for an elongated thin conductive sheet of material; said thin conductive sheet of material having a plurality of parallel fingers spaced along the width of said thin conductive sheet and folded at a generally common angle with respect to the direction of elongation of said sheet; each of said fingers overlying one another and extending beyond one edge of said elongated thin conductive sheet; said overlying fingers defining a terminal for said thin conductive sheet having a thickness approximately n times greater than said sheet where n is the number of fingers, and a width of approximately l/n times the width of said thin conductive sheet; each of said fingers having a successively decreasing width.

2. A terminal for an elongated thinconductive sheet of material; said thin conductive sheet of material having a plurality of parallel fingers spaced along the widthof said thin conductive sheet and folded at a generally common angle with respect to the direction of elongation of said sheet; each of said fingers overlying one another and extending beyond one edge of said elongated thin conductive sheet; said overlying fingers defining a terminal for said thin conductive sheet having a thickness approximately n times greater than said sheet where n is the number of fingers, and a width of approximately 1/ n times the width of said thin conductive sheet; each of said fingers bent at a slightly different angle to the side edge of said sheet thereby to define a generally fan-shaped arrangement.

ROBERT K. SCHAEFER, Primary Examiner. I, F. RUGGIERO, Assistant Examiner.

Therefore, as shown in FIGURE 14, when the 

1. A TERMINAL FOR AN ELONGATED THIN CONDUCTIVE SHEET OF MATERIAL; SAID THIN CONDUCTIVE SHEET OF MATERIAL HAVING A PLURALITY OF PARALLEL FINGERS SPACED ALONG THE WIDTH OF SAID THIN CONDUCTIVE SHEET AND FOLDED AT A GENERALLY COMMON ANGLE WITH RESPECT TO THE DIRECTION OF ELONGATION OF SAID SHEET; EACH OF SAID FINGERS OVERLYING ONE ANOTHER AND EXTENDING BEYOND ONE EDGE OF SAID ELONGATED THIN CONDUCTIVE SHEET; SAID OVERLYING FINGERS DEFINING A TERMINAL FOR SAID THIN CONDUCTIVE SHEET HAVING A THICKNESS APPROXIMATELY N TIMES GREATER THAN SAID SHEET WHERE N IS THE NUMBER OF FINGERS, AND A WIDTH OF APPROXIMATELY 1/N TIMES THE WIDTH OF SAID THIN CONDUCTIVE SHEET; EACH OF SAID FINGERS HAVING A SUCCESSIVELY DECREASING WIDTH. 